No need for TRUNC() function here. The SQL I gave should work just fine.

>wouldn't that be
>
>>SELECT * FROM VOTER ;
>> WHERE
>
>trunc(tdob)
>
> = to_date('12/31/1971', 'MM/DD/YYYY') ;
>> AND cvotstatus = 'A'
>
>?
>
>
>>Since you are just looking for 1 date, 12/13/1971, you could just write your SQL this way:
>>
>>SELECT * FROM VOTER ;
>> WHERE tdob = to_date('12/31/1971', 'MM/DD/YYYY') ;
>> AND cvotstatus = 'A'
>>
>>As for yuor observed performance difference, it is always better to use BETWEEN when a column value needs to be between 2 other values.